It is known that there are semiautomatic firearms (i.e. capable of recalling the movable masses after the shot, ejecting the cartridge case and loading new ammunitions) in which the breechblock and the barrel carry out different recoil strokes following expansion of the gases generated by the explosion. The barrel slides backwards together with the breechblock over a first portion, of smaller extent, and then stops and the breechblock continues its stroke over a second portion, of greater extent, being disengaged from the barrel. Barrel and breechblock are brought back to the percussion position by suitable return springs. During the return travel, the breechblock causes ejection of the cartridge case and loading of a new ammunition in the barrel.
In this regard, the public document EP 1 950 520 discloses a semiautomatic smooth-bore rifle comprising a frame provided with breech, a barrel slidably mounted on the frame relative to the breech, a breechblock-slider assembly that is slidable relative to the breech, and elastic means comprising a friction spring, which means is able to oppose the translational motion of said barrel.
The Applicant has felt the need to improve the movement mechanism of the barrel and the breechblock in semi-automatic short recoil firearms first of all for ensuring a greater liability and a smaller wear of the parts carrying out a relative motion.
In fact, the Applicant has noticed that during separation between barrel and breechblock in the recoil movement and/or recoupling of these elements during return to the percussion position, the contact between the parties in motion can lead to a quick wear of the parts, giving rise, as a result, to possible seizing.
In addition, the usually helical springs that are employed for return of the barrel and/or breechblock or for damping the impulse movements of said barrel and/or breechblock can be subjected to yield, over a long period of use. As a result, the accuracy and functional qualities of the arm are compromised.
In this context, the technical task underlying the present invention is to propose a short recoil firearm overcoming the aforesaid drawbacks of the known art.
In particular, it is an object of the present invention to propose a short recoil firearm capable of ensuring movement accuracy of the parts over time, the efficiency of same being maintained substantially unchanged.
In greater detail, the present invention aims at making available a short-recoil firearm ensuring a joined and integral movement of the barrel and breechblock during a first portion of the recoil stroke and a guided decoupling of the breechblock from the barrel during a second portion of the recoil stroke.